From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65217C433DB for ; Thu, 21 Jan 2021 16:13:00 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3FA0623A23 for ; Thu, 21 Jan 2021 16:12:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3FA0623A23 Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=dm-devel-bounces@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611245577; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=H0X3Pv2MRAH0e3RTooYacelAXzQeBSY58fYQaTknQN0=; b=JbWfSlZgBhg9+1EIv+eitqAxXxNYRoUrnHNHk44KbjlN+eEniVAb7AzK8rkVCk2edpO1R5 ifQr1pBnZLLX+88RCUz0ok3CsB+Ey1aVUR0PMko6/xRyE5K5d7ME+6Vyb2Aw+EuIwfNcwS X47Grh3rn4rkimhwMftgSX6XswJEsM0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-369-mezXQ6vAOaat-E2vfG5maA-1; Thu, 21 Jan 2021 11:12:55 -0500 X-MC-Unique: mezXQ6vAOaat-E2vfG5maA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 72A1FAFA8C; Thu, 21 Jan 2021 16:12:49 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3A7DC9D53; Thu, 21 Jan 2021 16:12:48 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 0BA28180954D; Thu, 21 Jan 2021 16:12:46 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 10LG9bOO027875 for ; Thu, 21 Jan 2021 11:09:37 -0500 Received: by smtp.corp.redhat.com (Postfix) id D36F510016F5; Thu, 21 Jan 2021 16:09:37 +0000 (UTC) Received: from localhost (unknown [10.18.25.174]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9B71A100AE42; Thu, 21 Jan 2021 16:09:34 +0000 (UTC) Date: Thu, 21 Jan 2021 11:09:33 -0500 From: Mike Snitzer To: Martin Wilck Message-ID: <20210121160933.GA4104@redhat.com> References: <20201210092459.81939-1-hare@suse.de> <29294c6553c7ec3d31e1bc3b9de524e9c7060f07.camel@suse.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-loop: dm-devel@redhat.com Cc: dm-devel@redhat.com, hch@lst.de Subject: Re: [dm-devel] dm: avoid filesystem lookup in dm_get_dev_t() X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Thu, Jan 21 2021 at 10:02am -0500, Martin Wilck wrote: > On Thu, 2020-12-10 at 18:11 +0100, Martin Wilck wrote: > > On Thu, 2020-12-10 at 10:24 +0100, Hannes Reinecke wrote: > > > dm_get_dev_t() is just used to convert an arbitrary 'path' string > > > into a dev_t. It doesn't presume that the device is present; that > > > check will be done later, as the only caller is dm_get_device(), > > > which does a dm_get_table_device() later on, which will properly > > > open the device. > > > So if the path string already _is_ in major:minor representation > > > we can convert it directly, avoiding a recursion into the > > > filesystem > > > to lookup the block device. > > > This avoids a hang in multipath_message() when the filesystem is > > > inaccessible. > > > > > > Signed-off-by: Hannes Reinecke > > > > Ack, although I believe the scsi/__GENKSYMS__ part doesn't belong > > here. > > > > Note that this is essentially a revert/fix of 644bda6f3460 ("dm > > table: > > fall back to getting device using name_to_dev_t()"). Added the author > > of that patch to CC. > > Mike, do you need anything more to apply this one? Do you want a > cleaned-up resend? It got hung up with Christoph correctly requesting more discussion, last linux-block/lkml mail on the associated thread I kicked off is here: https://lkml.org/lkml/2020/12/23/76 Basically if Hannes or yourself would like to review that thread and send a relevant v2 it'd really help move this forward. I'm bogged down with too many competing tasks. You guys may be able to act on this line of development/fixing quicker than I'll get to it. Thanks, Mike -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel